Actinide speciation is the controlling mechanism to transport in the environment, and this transport is fundamentally a spatial phenomenon. With the use of MRI and a lanthanide contrast agent, we are able to investigate actinide transport to better understand the speciation of actinides, since the lanthanide contrast agent (Gd3+) also acts as a chemical analog to the trivalent actinide ions (primarily Am and Cm). With an increased understanding of actinide transport and speciation, we can improve our modeling to predict the dominant release and migration rates of actinides from radioactive waste repositories.